1. Field of the Invention
The present invention relates to a clamp/alignment mechanism to hold (support) and align information recording mediums, such as CD (Compact Disc) and DVD (Digital Versatile Disc), on a turntable, and an information-reproducing mechanism and an information-recording mechanism both of which are equipped with the clamp/alignment mechanism.
2. Description of the Related Art
There have been widely known information-recording/reproducing mechanisms which are able to read out and write bits of information onto and from information recording mediums including CDs (such as CD-ROM, and CD-R) and DVDs (such as DVD-ROM, DVD-R, and DVD-R/W). It is required in general for such an information-recording/reproducing mechanism that the positional relationship between a recording medium and a pickup for reading and writing bits of information be kept with precision. Whenever the positional relationship between a disk under rotation and the pickup is changed, reading and writing bits of information is no longer performed with precision, resulting in a degraded quality of music and videos (images) when reproduced. In addition, the disk is generally made of synthetic resin, which makes it easier to give dimensional irregularities to the diameters of central holes of disks when manufactured, the central holes being used to be loaded onto a turntable. If the inner diameter (i.e., the diameter of a central hole) of a disk is misaligned in the radial direction, the disk cannot be loaded (mounted) concentrically on the turntable, thus causing eccentricity.
To overcome this problem, a conventional information recording/reproducing mechanism is provided with not only a disk clamping mechanism to hold a disk but also an alignment mechanism that is able to reduce the situation where the disk is placed eccentrically on the turntable. FIG. 1 exemplifies a conventional clamp mechanism, which is equipped with a conventional information recording/reproducing mechanism, with which a disk is clamped on a turntable. The clamp mechanism shown in FIG. 1 is provided with an aligning blade spring 1 serving as an alignment mechanism. The aligning blade spring 1, which can be deformed elastically, is loaded in a turntable so that the spring can be oscillated toward a rotary shaft 2 of a rotary motor. In addition, the aligning blade spring 1 is made to forcibly touch the inner circumferential edge 6 (i.e., the central hole) of a disk 5 mounted and held (supported) on a turntable 3 with the use of a clamp member 4 pressing the disk 5 downward. This construction allows the disk 5 to be pushed outwardly, whereby the disk 5 can be aligned in its radial direction.
However, the conventional information recording/reproducing mechanism has a problem caused when the disk 5 is mounted onto the turntable 3. That is, for mounting the disk 5 onto the turntable 3, the disk 5 is obliged to push the aligning blade spring 1 downward, so that the spring 1 can be moved away from the space needed for mounting the disk 5.
Therefore, since there is caused a situation in which the disk 5 is forcibly laid on the aligning blade spring 1, the disk 5 is apt to be affected by the aligning blade spring 1. It is therefore difficult to provide a stable alignment and clamping operation. Additionally, there is an effect from the aligning blade spring 1, because a load necessary to press down the disk 5 (that is, a clamping force) is necessarily. required. Thus this gives rise to the need for an extra load for operation, which becomes another problem of the conventional clamp mechanism.